Stabilization of synthetic rubbers



United States Patent Ofiice 3,927,348 Patented Mar. 27, 1952 Thisinvention relates to new mixed aliphatic mononuclear aryl, i.e. alkylmononuclear aryl and alkenyl mononuclear aryl esters of phosphorous acidderived from monohydric saturated and unsaturated alcohols andmonohydric mononuclear phenols.

The invention relates further to a process for the production of theabove mentioned esters of phosphorous acid and esters derived from diand polyhydroxy alcohols such as ethylene glycol, glycerol, propyleneglycol, pentaerythritol and trimethylene glycol. The alcohols may beprimary or secondary alcohols and the hydrocarbon groups thereof may bestraight chain or branched and saturated or unsaturated and one or morehydrogens thereof may be substituted by inactive substituents such ashalogen.

More particularly the invention relates to phosphite esters of thegeneral formula in which in and n are integers and the sum thereof is 3,R is an aliphatic, i.e. alkyl or alkenyl radical of the group consistingof allyl, 3-cyclohexen-l-ylmethyl, Z-ethylhexyl, n-octyl, isooctyl,nonyl, decyl, dodecyl, oleyl and octadecyl, R and R are members of thegroup consisting of hydrogen and methyl and R is a member the groupconsisting of hydrogen, methyl, nonyl, octyl isopropyl and tert-butyland in which not more than one of R R and R is an aliphatic group.

The invention relates further to stabilized mixtures of vinyl resins andsynthetic rubbers with phosphite esters of the above general formula.

The alkyl and alkenyl aryl esters of this invention are generally nearlycolorless liquids having mild characteristic odors. These new estershave utility in stabilizing vinyl resins toward thermal discoloration.To this application they are Well suited with regard to compatibilitywith the resin, odor, etc.

They are eificaceous also for the stabilization of GR-S synthetic rubbertoward thermal discoloration. In fact, they are unique in that they arethe only stabilizers known to us which cause a bleaching out of thecolor originally present in the GR4, stock. In addition they preventsurface crust formation caused by decomposition during heating. In thisapplication they are well suited with regard to compatibility with thesynthetic rubber stock, odor, etc.

The compounds or compositions of this invention may be pure monoalkyl ormonoalkenyl diaryl phosphites, pure dialkyl or dialkenyl monoarylphosphites or mixtures thereof along with a small amount of trialkyland/ or trialkenyl and/or triaryl phosphites. The amounts of thetrialkyl, trialkenyl and triaryl phosphites present have not beendetermined but never have been found to be sufficient to requirepurification for their removal. The tri compounds are not harmfulexcepting in so far as they.

act as diluents or inert material. These compositions may Un1ess notedotherwise, the term octyl signifies p-1,1,3,3- tetramethylbutylphenyl.92-95% is the para-isomer the balance is the ortho-rsomer. See Rohm andHaas Bulletin SP-98, June 1954, page 1.

be prepared from relatively pure diaryl phosphorochloridites, relativelypure monoaryl phosphorodicliloridites or mixtures thereof along withsmall amounts of phosphorus trichloride and/ or triaryl phosphit-es.

In the new process of our invention the requisite monoor diarylphosphorohalidite, usually the phosphorochloridite, is caused to reactwith the calculated equivalent or an excess of an aliphatic alcohol withthe simultaneous admission of anhydrous ammonia so that the reactionmixture is maintained substantially neutral.

The preparation of the mixed aliphatic aryl phosphites from the arylphosphorochloridites and alcohols may be shown by the followingequations:

AI'OPCIg-I-ZROH ArOP OR) +2HC1 (ArO) PCl+ROH- (ArO) POR-l-HCI If thesereactions are carried out without removal of the hydrogen chloride as itis formed, the mixed triester prod nets are immediately decomposed tothe corresponding acid phosphites. (Milobendzki and Szulgin ChemikPolski 15, 66-75 (1917). The following equations illustrate this:

In the past, in processes of making other phosphite esters, this sidereaction has been prevented either by the use of a tertiary amine(usually pyridine) to remove the hydrogen chloride as it is formed byformation of the insoluble pyridine hydrochloride (Milobendzki andSzulgin Chemik Polski, 15, 6675 (1917) (CA 13: 2867 (1919)) or by theuse of sodium alkoxide in the original reaction (Arbuzov and Valitova,Izvestiya Akad. Nauk S.S.S.R., o.k.h.n., 1940, 529 (CA 35: 3990 (1941))and Arbuzov and Valitova, Trudy Kazan Khim Teirhnol. Inst., 8,12 (1940)(CA 35: 2485 (1941)).

Neither of these methods of neutralization is economical for commercialoperations in making the compounds of our invention. In the tertiaryamine: method (which uses an inert solvent) the procedure is quiteexpensive and any commercial adaptation necessitates the tedious andcostly recovery, purification and reuse of the organic base. With sodiumalkoxides the yields are low and the desired mixed tertiary ester iscontaminated with considerable amounts of undesired by-products.

Because of these drawbacks to the known preparative methods which startwith phosphorochloridites, an alternative synthetic approach has beenused in the past for laboratory operations. This laboratory methodemploys triaryl phosphite and this starting material is forced toundergo ester interchange with an alcohol or an alkoxide. With alcoholsthe method is limited by the lack of reactivity of most alcohols atreasonable temperatures and by a tendency toward isomerization to thecorresponding phosphonate at the elevated temperatures required toobtain a reasonable reaction rate (Milobendzki and Szulgin, ChemikPolski,15, 6675 (1917) (CA 13: 2867 (1919)).

Ester interchange occurs readily when an excess of an alkali metalalkoxide is heated with a triaryl phosphite. The commercial utility ofthis synthetic method is limited since the yields are lower than thoseusing aryl phosphorochloridites with alcohols and tertiary amines andthe danger of handling metallic alkoxides is an obvious drawback.

The aryl phosphorochloridites, which are the raw materials for our newprocess, may be prepared conveniently by either of two methods. Onemethod involves heating together suitable portions of a triarylphosphite and phosphorus trichloride which permits the followingreversible reaction to take place. [Conant,

3 Wallingford and Grandheker, I. Am. Chem. Soc., 45, 762 (1923)].

(ArO) P+PCl -(ArO PCl+ArOPCl In this equation Ar stands for a broadvariety of aryl radicals including any one of the substituted arylgroups described above. The position of the equilibrium varies with therelative proportions of the reagents used according to the law of massaction.

A second method which may be employed requires warming together suitableportions of the requisite phenol and phosphorus trichloride whereuponreaction takes place as follows. [Menshutkin, Ann., 139, 343 (1866)]:

In this equation Ar has the same meaning as in the foregoing paragraph.This reaction is not an equilibrium type but the relative proportions ofthe three aromaticcontaining products and of unreacted phosphorustrichloride vary With the relative proportions of the reagents used.Generally speaking the higher is the phenol ratio the greater are theamounts formed of diaryl phosphorochloridite and triaryl phosphite.Conversely, the higher is the ratio of phosphorus trichloride thegreater are the amounts of monoaryl phosphorodichloridite and unreactedphosphorus trichloride remaining at the end of the reaction period.

The general experimental write-up below shows one procedure used in thepreparation of the mono and diaryl phosphorochloridites.

METHOD A (ArO P +PCl =(ArO) PCl-|-A1"OPC1 Phosphorus trichloride and theappropriate triaryl phosphite, in the ratio of 1.5 moles to 1.0 molerespectively, were placed in the reaction vessel equipped with a sealedstirrer, a reflux condenser and a thermometer. The mixture was heated atreflux for a period ranging from 4.5 to 5.5 hours. The temperature wasallowed to increase to a maximum of 140 C. The resulting mixture wasfractionally distilled to obtain the desired pure mono and diarylphosphorochloridites. Disti1la tion was not necessary in the preparationof technical mixtures of dialkyl monoaryl phosphites with monoalkyldiaryl phosphites. The following experimental examples show specificallythe preparation of the aryl phosphorochloridites by Method A.

Example I DIPHENYL PHOSPHOROCHLORIDITE AND PHENYL PHOSPHORODICHLORIDITEOne hundred twenty-four grams of phosphorus trichloride and 186 g. oftriphenyl phosphite were mixed and heated at reflux for a total of 5hours, during which time the reflux temperature increased from 85 C. to140 C. Fractional distillation of the resulting mixture gave 66 g. ofdiphenyl phosphorochloridite, n 1.5760, r1 1.242, B.P. 110-113 C./0.4mm. and 84.5 g. of phenylphosphorodichloridite, n 1.5380, 11 1.353, B.P.8690 C./ mm., as well as other mixed fractions which contained inaddition to the two above compounds, some unreacted phosphorustrichloride and triphenyl phosphite.

Example II DlI-p-TOLYL PHOSPHOROCHLORIDITE AND p-TOLYLPHOSPHORODICHLORIDITE One hundred twenty-four grams of phosphorustrichloride and 214 g. of tri-p-tolyl phosphite were mixed and heated atreflux for a period of 4 /2 hours, during which time the refluxtemperature increased from 80 C. to 110 C. Fractional distillation ofthe resulting mix- 4 ture gave 50.8 g. of di-p-tolylphosphorochloridite, ru 1.5624, d 1.188, B.P. 138-140 C./0.08 mm.

AnaL-Calcd: P, 11.03; Cl, 12.64. Found: P, 10.98; Cl, 12.83.

There was also obtained 26.8 g. of p-tolyl phosphorodichloridite, n1.5478, d, 1.304, B.P. 103- 106 C./10 mm.

Anal.Calcd: P, 14.81; Cl, 33.96. Found: P, 15.72, 15.78; Cl, 33.98.

Other fractions were also obtained which contained, in addition to smallamounts of the above compounds, some unreacted phosphorus trichloride,and tri-p-tolyl phosphite.

The general experimental write-up below shows the second procedure usedin the preparation of the mono and diaryl phosphorochloridites.

METHOD B Phosphorus trichloride and the appropriate phenol, in the molarratio of 1 to 1 or 1 to 2, were mixed in the reaction vessel equippedwith a sealed stirrer, a dropping tunnel (or solid addition tube), athermometer and a reflux condenser. The condenser was connected to anaspirator through a Dry Ice trap in order to remove phosphorustrichloride that might be entrained during hydrogen chloride evolution.

The phenol and phosphorus trichloride were either mixed in the vesselinitially, or mixing was accomplished by slowly adding the phenol, as asolid or liquid, or a. a solution in an inert solvent, to the stirredphosphorus trichloride. Addition time varied from about 0.5 to about 6.7hours. A slight negative pressure (approx. 1 atm.5 mm.) sometimes wasmaintained during this period to facilitate removal of the hydrogenchloride gas, and when suflicient phosphorus trichloride accumu-- latedin the Dry Ice trap, it was returned to the reaction vessel.

After the phenol addition was completed, the pressure was decreased to aminimum of about 1 mm. and the temperature was increased to a maximum ofabout C. Total reaction time varied from about 1.67 to about 6.7 hours.The resulting mixture was fractionally distilled to obtain the desiredpure mono and diaryl phosphorochloridites. Distillation was notnecessary in the preparation of technical mixtures of dialkyl monoarylphosphites with monoalkyl diaryl phosphites.

The following experimental examples show specifically the preparation ofthe aryl phosphorochloridites by Method B.

Example III DI-o-TOLYL PHOS-PHOROCHLORIDITE AND o-TOLYLPHOSPHORODICHLORIDITE A mixture of 216.6 g. of o-cresol, and 137.4 g. ofphosphorus trichloride was heated gradually from 25 C. to 60 C. over aperiod of 4 /2 hours. During the last hour of heating, reduced pressurewas gradually applied to aid in removal of the hydrogen chloride, sothat at the end of the reaction, 94% of the theoretical amount of thehydrogen chloride had been removed, and a pressure of mm. had beenobtained. By fractional distillation of this mixture, there was obtained22.0 g. of o-tolyl phosphorodichloridite, n 1.5514, 11 1.306, B.P. 9810lC./11 mm.

Anal.-Calcd: P, 14.85; Cl, 33.96. Found: P, 14.83; C1, 33.94.

There was also obtained 122.5 g. of di-o-tolyl phosphorochloridite 111.5666, df" 1.193, RR 139 C./0.05 mm.

Anal.-Ca1cd: P, 11.03; Cl, 12.63. Found: P, 10.97; Cl, 12.64.

Example IV BIS(p-OCTYLPHENYL) PHOSPHOROCHLORIDITE AND p-OCTYLPHENYLPHOSPHORODICHLORIDITE Two hundred sixty-five grams of p-octylphenol and176 g. of phosphorus trichloride were mixed and heated gradually to atemperature of 70 C. over a period of 6 hours while gradually decreasingthe pressure by means of a water aspirator pump to a final pressure of30 mm.

The hydrogen chloride which was formed during reaction was almostcompletely removed. Total crude yield was 321 g.

Fractional distillation of 188 g. of the resulting mixture gave 36.2 g.of bis(p-octylphenyl) phosphorochloridite, B.P. 215222 C./0.5 mm., and65.9 g. of p-octylphenyl phosphorodichloridite, B.P. 132-150 C./ 1.5mm., as well as other fractions which contained phosphorus trichlorideand tris(p-octylphenyl) phosphite.

Example V BIS(p-NONYLPHENYL) PHOSPHOROCHLORIDITE AND p-NONYLPHENYLPHOSPHORODICHLORIDITE Four hundred grams of mixed nonyl-phenols (containing mostly para-isomers) and 123.4 g. of phosphorus tria chloride weremixed and heated gradually to a temperature of 80 C. over a period of 4/2 hours. During the last two hours of reaction, the pressure wasgradually decreased by means of a water aspirator pump to a finalpressure of 30 mm. The hydrogen chloride which was formed duringreaction was nearly completely removed. The total crude yield was 450.4g.

Fractional distillation of this mixture gave 172.5 g. ofbis(p-nonylphenyl) phosphorochloridite, B.P. 220-231 C./0.15 mrn., n1.5238.

Anal.Calcd: P, 6.13; Cl, 7.02. Found: P, 6.07; CI, 7.22.

There was also obtained 27.6 g. of p-nonylphenyl phosphorodichloridite,B.P. 130135 C./0.l5 mm., n 1.5139, 11 0.987.

Anal.-Calcd: P, 9.65; Cl, 22.08. 8.92; Cl, 21.86.

Other fractions were obtained which contained phosphorus trichloride andtris(nonylphenyl) phosphite in addition to the two above describedcompounds.

Example VI TECHNICAL MIXTURE OF BIS(p-OCTYLPHENYL) PHOS- PHOROCHLORIDITEAND p-OCTYLPHENYL PHOS- PHORODICI-ILORIDITE FROM 2:1 MIXTURE OF THEPHENOL AND PCls To 68.7 g. of phosphorus trichloride was added at 55 C.a solution of 206.3 g. of p-octylphenol in 250 ml. of benzene over aperiod of one hour while evacuating the reaction flask very slightly tofacilitate the removal of the hydrogen chloride which was liberatedduring the reaction. Heating at 55 C. was continued for a total of 5hours, and the vacuum was gradually increased during the last hour sothat at the end of this period a pressure of 120 mm. was obtained. Thetheoretical amount of hydrogen chloride and most of the benzene solventwas removed during the heating period. Finally, the vacuum was increasedto 1 mm, and the pot temperature increased to 80 to remove the remainingbenzene. The total crude yield was 221 g. This mixture was analyzed andshown to contain 2.47 milliequivalents of reactive chlorine (ie.chlorine attached to phosphorus) per gram (quantitative distillationmethod).

Example VII TECHNICAL MIXTURE OF BIS (p-OCTYLPHENYL) PHOS-PHOROCHLORIDITE AND D'OCTYLPHENYL PHOS- PHORODICHLORIDITE FROM 1 :1MIXTURE OF PHENOL AND PCls This product was obtained as the crude yieldin Exam- Found: P, 9.16,

ple IV and contained 4.59 milliequivalents of reactive chlorine pergram.

Example VIII TECHNICAL MIXTURE OF DI-m (AND tl)-TOLYL PHOS-PHOROCHLORIDITE AND 111 (AND p)-TOLYL PHOS- PHORODICHLORIDITE FROM 2:1MIXTURE OF PHENOL AND PCla To a 137.4 g. of phosphorus trichloride wasadded with stirring 216.2 g. of a technical mixed m (and p)-cresol at C.over a period of 3 hours, while maintaining a slight vacuum tofacilitate the removal of the hydrogen chloride which was'liberated.Heating at 55 C. was continued for a total of 6 /2 hours. The vacuum wasgradually increased to a final pressure of 24 mm. during the last hourof heating to remove all of the hydrogen chloride. This mixture wasshown to contain 2.33 milliequivalents of reactive chlorine per gram(quantitative distillation method).

Example IX TECHNICAL MIXTURE OF DI-m (AND p)-'IOLYL PHOS PHOROCHLORIDITEAND m (AND p)-TOLYL PHOS- PHORODICHLORIDITE FROM 1:1 MIXTURE OF PHENOLAND PCls To 137.4 g. of phosphorus trichloride was added 108.1 g. of atechnical mixed m (and p)-cresol over a period of 40 minutes at atemperature of 55 C. While maintaining a slight vacuum to facilitate theremoval of the hydrogen chloride. Heating at 55 C. was continued for atotal of 5 hours. The vacuum was gradually increased during the lasthour of heating to a final pressure of mm. to re move all of thehydrogen chloride. This mixture was shown to contain 7.28milliequivalents of reactive chlorine per gram.

Example X TECHNICAL LIIXTURE OF 'DIPHENYL PEIOSPI-IORO- CHLORIDITE ANDPHENYL PIIOSPI'IORODICHLORI- DITE FROM: 2:1 MIXTURE OF THE PHENOL ANDPO13 To 687 g. of phosphorus trichloride was added with stirring at40-45 C. 941 g. of molten phenol over a period of 40 minutes. Thereaction mixture was warmed gradually to C. over a period of 2% hours.During this time a very slight vacuum was applied to facilitate removalof the hydrogen chloride. During the last hour of heating at 75 C. thevacuum was increased to a final pressure of 40 mm. to remove all of thehydrogen chloride. This mixture was shown to contain 3.28milliequivalents of reactive chlorine per gram (V olhard method).

Example XI TECIINICAL BIIXTURE OF DIPI'IENYL PIIOSPIIORO- CHLORIDITE ANDPIIENYL PIIOSPEIORODICIILORI- BITE FROM: 121 DIIXTURE OF THE PHENOL ANDPO11;

To 686.8 g. of phosphorus trichloride was added with stirring at 30-35C. 470.5 g. of molten phenol over a period of 25 minutes. The reactionmixture was warmed to 75 C. over a period of 10 minutes, and maintainedat this temperature for 1 /2 hours at atmospheric pressure. During thenext 1 /2 hours at 60 C., the pressure was gradually decreased to 47 mm.to remove the last of the hydrogen chloride. This mixture was shown tocontain 6.83 milliequivalents of reactive chlorine per gram (Volhardmethod).

Data concerning more aryl phosphorochloridites prepared by Method B ispresented in the table below.

8. time has obviated the undesirable reactions of ammonia with arylphosphorochloridites.

DATA ON ARYL PHOSPHOROCHLORIDITES Ratio of Total Percent phenolto Temp.reaction yield of 0. 0. Boiling point Name Alcohol used PO1 range timeexpected no d O./mm.

(Molar) 0.) (hours) product Phenyl phosphorodichloridite 1:1 45-95 4.2526.2 filo/0.23 Diphenyl phosphorochloridite..- 1 :1 45-95 4.25 10. 3my 1. 5774 (14 1.246 122/0. 45 Tolyl phosphorodichloridite 1 :1 10-70 1.67 41. 5 n 1. 5538 114 1. 287 72/0. 30 Ditolyl phosphorochloridite 1 :119-70 1.67 21. 8 146/0. 30: Isopropylphenvl phosphorodichloridite 1:110-50 3. 5 38. 5 no 1. 5378 11 1.227 90-92/004 Bis(isopropy1phenyl)phosphorochlorid e o 1:1 10-50 3. 5 21.2 7113 1. 5450 d4 1.104177-182/023 p-Tert-butylphenyl phcsphorodichloridite p-Tert-butylplienol1:1 40 2.0 34.0 71.13 1. 5333 di 1.188 87-92/015 Bis(p-tert-butylpheny1phosphoroch1oridite do 1:1 40 2.0 26.8 11.13 1.5398 (1 1.086 180-181.5/0. 01 p-Octylphenyl phosphorodichloridite p (Octyl) phenol" 1:1 19-500.1 41. 8 97.13 1. 5242 114 1.124 130 0.07 Bis(p octylphenyl)phosphorochloridite Octylphenol 1:1 19-50 6.1 22.1 'n 1. 5292 d4" 1.030220/011 1 Percent yield was calculated assuming only one product wasformed.

By the process of our invention the aryl phosphorochloridites preparedby either of the above two methods, either in a purified form or as acrude reaction product, may be smoothly converted to alkyl or alkenylaryl phosphites without the use of expensive tertiary organic bases ordifficult-to-handle alkali metal alkoxides. In our process we use thecheap, readily available, anhydrous ammonia. Our procedure provides acommercially practical method of preparing in high yields tertiary alkyland alkenyl aryl phosphites substantially free of secondary esters.

Broadly stated we simultaneously add ammonia and an arylphosphorochloridite to an aliphatic alcohol. Reactions of the mono anddiaryl phosphorochloridites may be represented by the followingequations:

(1) ArOPCl +2ROH+2NH ArOP (OR) +ZNH CI (2) (ArO) PCl+ROH+NH (ArO) POR+NHCl In addition to the useful aliphatic aryl phosphites obtained by thereactions, by-product ammonium chloride can be recovered and used as afertilizer material or treated with alkali or lime to regenerate ammoniafor reuse.

Anhydrous ammonia as an agent for removal of hydrogen chloride liberatedin these reactions has heretofore been considered impractical since itreacts under ordinary conditions with aryl phosphorochloridites to formaryl phosphoramidous compounds. Illustrative reactions are as follows:

(1) AIOPCl2+ 4NH ArOP (NI-I +2NH Cl Undoubtedly many more complexreactions also occur.

It should be clearly understood that tertiary amines commonly used inlaboratory practice are not subject to reaction with arylphosphorochloridites in the above manner since these tertiary amineshave no replaceable hydrogen on the nitrogen atom. This invention therefore has accomplished the removal of the corrosive hydrogen chloridegenerated in the reaction and at the same Our invention, morespecifically, comprises the preparation of alkyl and alkenyl arylphosphites by the addition of aryl phosphorochloridites to at least thetheoretical amount of an aliphatic alcohol, which may or may not bediluted with an inert solvent, accompanied by the simultaneous additionof dry ammonia so that the liberated hydrogen chloride is justneutralized. The ammonium chloride formed is removed and uponevaporation of solvent or excess alcohol, an aliphatic aryl triester isobtained which is relatively free of diester and phosphorus amidocompounds. This product may be further purified by simple distillation.

In carrying out the process of this invention the optimum temperaturevaries with the amount of solvent used, the efiiciency of stirringduring the mixing of the reactants, and with the number of carbon atomscontained in the aliphatic chain of the alcohol. Generally the optimumtemperature lies within the range from about -10 C. to about 60 C.

With regard to the quantities of reagents used, at least the theoreticalamount of alcohol should be used. An excess of alcohol givessatisfactory results.

Many inert solvents, e.g. ether, hexane, heptane, benzene, toluene,etc., are suitable for diluting the alcohol before reaction. A largeexcess of alcohol may serve as a solvent. However, alcohols solubilizeammonium chloride to some extent and thus the use of excess alco- 1101makes complete removal of this salt diflicult. Ammonium chloride is mostconveniently removed by washing with water. Since phosphites whichcontain aliphatic groups are somewhat sensitive to acid hydrolysis incontact with water, it is preferred that wash solutions be maintained inan alkaline state by the addition of a suitable amount of alkali metalhydroxide, alkaline earth metal hydroxide, or other suitable base.

When an inert solvent is used, it is preferred to dilute not only thereactant alcohol but also the aryl phosphorochloridite with the inertsolvent. While large excesses of inert solvents give uniformly goodresults, the use of too small an amount in some cases prevents goodstirring and permits localized attack of the hydrogen chloride on theproduct triester. The minimum amount of solvent required for bestresults increases as the efiiciency of stirring decreases and decreasesas the reaction temperatures are lowered. Generally speaking, in theusual procedure the use of 2 to 3 parts of solvent per part of finalproduct expected gives satisfactory results.

The rate of ammonia addition is regulated so that the reaction mixturestays essentially at the neutral point. If the reaction mixture isallowed to remain quite acidic during the entire reaction, almost noneof the desired triester is obtained. Instead the corresponding diester(one alkyl group is removed from the triester) is the main product. Ifthe reaction mixture is allowed to remain quite basic, or even under apositive pressure of ammonia, the yield of triester is unsatisfactoryand the final product is frequently contaminated with phosphoramidousside-reaction products.

We have found that for laboratory operations a convenient way to controland balance the ammonia and aryl phosphorochloridite additions, so thatneutral conditions are maintained, is by the use of a suitable acid baseindicator added to the reaction mixture. While many indicators can bemade to serve, the azo types, e.g. methyl red and methyl orange, givethe most easily followed color changes. These indicators are verysensitive giving their characteristic acid color in the presence ofhydrogen chloride (i.e. aryl phosphorochloridite) and theircharacteristic basic color in the presence of excess ammonia. Thephthalein type indicators, e.g. alizarin red S, bromcresol purple,bromthymol blue, thymol blue and thymolphthalein, tend to decolorize orgive less satisfactory color changes during the course of the reaction.Malachite green and p-nitrophenol also are less satisfactory than theazo type indicators mentioned above.

While the invention is illustrated by the indicator method of observingand maintaining neutral conditions of reactions, the invention is notlimited to this method since any method of observing and maintainingneutral conditions (conductiometric, spectrophotometric, electronic,simple stoichiometric addition, etc.) falls within the scope of ourinvention.

The aliphatic aryl phosphite products of our invention are useful in thepreservation of synthetic rubber-like (elastomeric) latex materials andmore particularly those derived from modified 1,3-diene polymers whichare formed from the polymerization of conjugated dienes, especiallythose known to the trade as Buna S (GRS) Latex. The various syntheticelastomers are known by the art to be produced in various manners. Thepresent invention is not concerned with the particulars of producingthese elastomers but in their preservation as stated above.

The triaryl phosphites have been used for the preservation of syntheticrubbers. The compounds of our invention are superior to these triarylphosphites, as will be illustrated, and in addition our aliphatic arylphosphites serve to actually bring about a bleachng-out of the rubbercolor as aging progresses. Normally all synthetic rubber stocksgradually darken on aging. This darkening is definitely harmful to thesale of these stocks for use in white or light-colored products. As willbe illustrated, even the stabilized or preserved rubber stocks whichcontain the triaryl phosphites measurably darken on aging. The compoundsof our invention, however, show a very definite, measurable, andreproducible improvement of color on aging. Instead of a mere decreasein normal darkening with age the aliphatic aryl phosphites of ourinvention actually improve the original color and the result is ableaching-out as the rubber ages.

This result is new and unpredictable from anything heretofore reportedin the art. Commercially this is a highly useful result and enablesrubber products which contain the aliphatic aryl phosphites of ourinvention to be used for White and light-colored, for example lightpastel dyed, rubber objects.

Furthermore synthetic rubber latex compounded to contain the products ofour invention shows a Mooney viscosity change which is diiTerent fromthat of similar stocks compounded with the triaryl phosphites of theprior art. As is illustrated below the Mooney viscosity of anunstabilized material gradually rises indicating an equally gradualundesirable toughening on aging. The rubber sample which contains thetriaryl phosphite of the prior art first softened (drop in Mooney) andthen rose back to a fairly constant level. The aliphatic aryl phosphitesof our invention prevent the rise in Mooney without the initial dip orsoftening shown by the triaryl stabilized products. This is new, unusualand unpredictable from the prior art and indicates a more stable productand more stabilizing activity by the aliphatic aryl phosphites of. ourinvention.

The aliphatic aryl phosphite stabilizer (1.25% by weight based on thelatex solids.) was added in the form of an aqueous dispersion to GR-S734Latex. The latex was adjusted to a pH of 10 ($0.2) and the polymer wascoagulated with brine and acid to form a granular precipitate which waswashed thoroughly, dried in a 60 C. circulating air oven and sheeted outon a rubber mill (ref. Reconstruction Finance Corp. Report AU-926,Project 407-S, April 16, 1951). The following table illustrates thestabilizing activity of the aliphatic aryl phosphites as compared to thetriaryl phosphites of the prior art and also unstabilized material.

Hours Surface Mooney Sample aging at Color 1 film or viscosity 100 C.crust 100 G.

Control (no stabilizer) 0 3 N one.. 47 2 3 Yes. 46 4 4 Yes- 47 8 4 Yes.48 24 5 Yes. 49 48 5 Yes. 50 lris(p oetylphenyDphosphite 0 1 None 45(Commercial product predomt 2 1 None.. 42 nantly this compound). 4 2None. 38 8 2 None" 39 24 2 None" 41 48 2 N one 42 Z-ethylhexyl bis(p-octylphenyl phos- 0 2 N one 44 phite. 2 1 None. 44 4 l N one 45 8 O None 46 24 0 None.. 41 48 0 None 44 2-ethylhexyl diphcnyl phosphite. 0 3N one. 47 2 2 None 47 4 1 None 47 8 0 None 47 24 0 None. 49 48 0 None.Bis(2-ethylhexyl) phcnyl phosphite 0 3 None 43 2 3 None- 42 4 1 None 448 0 None 44 24 O Nonc 48 0 N one.. 43

1 Color: 0:n0 color, excellent; lzslight color, very good; 5:poor, darkcolor.

All of the compounds of our invention show activity and results similarto those shown in the foregoing table.

The general experimental write-up below shows the procedure used in thepreparation of the pure monoalkyl diaryl phosphites and the pure dialkylrnonoaryl phosphites of our invention.

Procedure for Preparation of Pure Monoalkyl Diaryl Phosphites and PureDialkyl Monoaryl Phosphiles The appropriate pure mono or diarylphosphorochloridite, alone or dissolved in an inert solvent, was addeddropwise, with stirring, to at least a chemically equivalent amouht ofthe appropriate alcohol. The alcohol was diluted with an inert solventor excess alcohol was used as its own solvent. A sumcient amount ofmethyl red indicator was present to denote change from basicity toacidity. Reaction temperature varied from about 0 C. to about C.Simultaneously with the addition of the phos- 1 1 phorochloridite, dryammonia gas was bubbled into the reaction mixture in an amountsufficientto maintain the reaction mixture just basic to methyl red.

Upon completing the addition, stirring was continued for a short period.Total reaction time varied from about 5 minutes to about 73 minutes.

The vigorously stirred reaction mixture was then washed with thecalculated amount of 3.5% NaOH solution and/or 5% NaOH solution and/or10% NaOH solution and/ or 20% NaOH solution. Approximately 250 ml. of3.5% NaOH was used for every mole of NH Cl formed. Approximately 50 ml.of 10% NaOH was used for every mole of NH Cl formed.

The water and oil layers were separated. The oil layer was freed ofinert solvent or excess alcohol by reduced pressure distillation at apot temperature of about 90-97 C. and at 2-20 mm. pressure.

Distillation of the remaining oil gave the pure monoalkyl diarylphosphite or the dialkyl monoaryl phosphite, depending upon the startingmaterials used.

Our invention is illustrated with respect to both the broad process andthe relatively limited groups of useful esters by the followingexamples:

A. DIALKYL MONOARYL PHOSPHITES Example XII BIS (Q-ETHYLHEXYL) PHENYLPI-IOSPHITE Sixty-five grams of phenyl phosphorodichloridite prepared asdescribed in Example I was dissolved in 100 ml. of hexane, and thissolution was added dropwise to a stirred solution of 79 g. ofZ-ethylhexanol and 0.1 g. of methyl red indicator in 100 ml. of hexaneat a sutficient rate to keep the temperature at from to 5 C. whilecooling with an ice-salt bath. Simultaneously, dry ammonia gas wasbubbled into the reaction mixture at a .sufiicient rate to maintain themixture just basic to methyl red. A period of 63 minutes was requiredfor this addition. The reaction mixture was stirred for an additionalminutes after reaction, and the temperature was allowed to increase toabout 20 C.

To the vigorously stirred mixture was then added 200 ml. of 20% sodiumhydroxide solution, and stirring was continued for 10 minutes. The waterand oil layers were separated. The oil layer was freed of hexane bydistillation to a pot temperature of 100 C. at 20 mm., and the remainingoil was vacuum distilled. One hundred and one grams of bis(Z-ethylhexyl)phenyl phosphite was obtained, n 1.4791, at, 0.964, B.P. 148156 C./ 0.06mm.

Anal.--Calcd equivalent weight (iodometry): 191.3. Found: 196.2, 192.1.

Example XIII BIS Z-ETHYLHEXYL) o-TOLYL PHO SPHITE A solution of 16.7 g.of the o-tolyl phosphorodichloridite prepared in Example III in 40 ml.of hexane was added dropwise to a stirred solution of 21 g. of2-ethylhexanol, and 0.1 g. of methyl red indicator in 40 ml. of hexaneat a sufiicient rate to maintain a temperature of from 0 to 5 C. whilecooling with an ice-salt bath. Simultaneously, dry ammonia gas wasbubbled into the reaction mixture at a sufiicient rate to keep thesolution just basic to methyl red. Twenty-eight minutes was required forthis addition. The reaction mixture was stirred for an additional 10minutes, and the temperature allowed to increase to about 20 C.

P, 8.07, 8.12. Found:

Example XIV A solution of 20.9 g. of the p-tolyl phosphorodichloriditefrom Example II in 45 ml. of hexane was added dropwise to a stirredsolution of 27 g. of Z-ethylhexanol and 0.1 g. of methyl red indicatorin 45 ml. of hexane at a sufiicient rate to maintain the temperature atfrom 0 to 5 C. while cooling with an ice-salt bath. Simultaneously, dryammonia gas was bubbled into the reaction mixture at a sufiicient rateto keep the solution just basic to methyl red. Thirty minutes wasrequired for this addition. The reaction mixture was stirred for anadditional 10 minutes, and the temperature allowed to increase to about15 C.

To the vigorously stirred reaction mixture was then added 65 ml. of 5%sodium hydroxide solution, and stirring was continued for 15 minutes.The water and oil layers were separated, and the hexane was removed fromthe oil layer by distillation to a pot temperature of C. at 20 mm. Theresulting oil on distillation gave 27.9 g. of bis(2-ethylhexyl) p-tolylphosphite, n 1.4738, [1 0.946.

Anal.-Calcd.: P, 7.81. alent weight (iodometry): 198.3.

Found: 7.55. Calcd equiv- Found: 202.0, 200.8.

Example XV BIS(2ETHYLHEXYL) p-OCTYLPHENYL PHO SPHITE A solution of 96.3g. of p-octylphenyl phosphorodichloridite, prepared as in Example IV in186 ml. of hexane was added dropwise to a stirred solution of 81.7 g. of2-ethylhexanol and 0.1 g. of methyl red indicator in 186 ml. of hexane.The addition was carried out at such a rate as to keep the temperatureof the reaction mixture at 812 C. Simultaneously, dry ammonia gas wasbubbled into the reaction mixture at a sulficient rate to maintain thesolution just basic to methyl red. Seventeen minutes was required forthis addition. The reaction mixture was stirred for 10 minutes, and thetemperature was allowed to increase to about 20 C.

To the vigorously stirred mixture was added 157 ml. of 3.5 sodiumhydroxide solution, and stirring was continued for 10 minutes. Anemulsion was obtained, and separation of the water and oil layers wasaccomplished with some difi'iculty. The hexane was removed from the oillayer by distillation at a pressure of 20 mm. to a pot temperature of100 C. The product bis(2-ethylhexyl) p-octylphenyl phosphite weighed 129g. n 1.4828, 1 0.935.

AnaL-Calcd equivalent weight (iodometry): 265.58. Found: 280.5, 280.5.

The table below gives experimental and analytical data on additionaldialkyl monoaryl phosphites that were prepared by the same generalexperimental procedure as shown previously.

Found ZQr -kUhUnunnOOZ 2443992158 Calcd Analytical (percent) Calcd.

time min.

U 4 2 3 ic ldf om nnmfim Md 989 079087898 M v1 1 y P u m h 3 Hm 0.05505500 03 701 5 52222222 53 m d NW U .1 6 5705505500750 O(\ 2 5202200626 m 1 21 .11111111 A A5 Ne S u mnmmmnm aw 1111 D us 000000 005500B 511111111 22 B Trti 5057705070500 2331111213113 1 l sm 1 Example XVIIIMolar ratio Reaction alcohol: chloridite Found 239. 9, 238. 0 my 275. 5,290. 0 m) 6 nD 1 0 110 1 0 no 8 no Equivalent weight to increase to 20C. The ammonium chloride was removed by filtrations, and the filtratewas clarified by treatment with activated charcoal. The hexane wasremoved mm. to give 38 g. of allyl bis(p-nonylphenyl) phosphite,

aoawgeaa m n Calcd.

DIALKYL MONOARYL; PHOSPHITES OF THE GENERAL FORMULA The reaction mixturewas Identifying variables Example X VI -TOLYL PHOSPHITE ALLYL DI-o B.MONOALKYL DIARYL PHOSPHlTES A solution of 50.5 g. of the dioto-lylphosphorochloridite prepared in Example 111 in 79 ml. of hexane was Tothe vigorously stirred mixture was added 150 ml.

added dropwise to a stirred solution of 10.7 g. of allyl alcohol and 0.1g. of methyl red indicator in ml. of hexane at a rate sufiicient tomaintain a temperature of from 0 to 5 C. while cooling with an ice-saltbath. Simultaneously, dry ammonia gas was bubbled into the reactionmixture at a rate sufiicient to keep the solution just basic to methylred. A period of 43 minutes was required for this addition.

stirred for an additional 10 minutes, and the temperature was allowed toincrease to about 10 C.

hexen-l-methanol and 0.1 g. of methyl red indicator in m1. of hexane ata rate suflicient to maintain a temperature of from 0 to 5 C. whilecooling with an ice-salt bath. Simultaneously, dry ammonia gas wasbubbled into the reaction mixture at a sulficient rate to keep it justbasic to methyl red. A period of 37 minutes was required for thisaddition. The reaction mixture was stirred for an additional 15 minutes,and the temperature was 65 allowed to increase to about 20 C. Theammonium chloride was removed from the reaction mixture by filtration,and the filtrate was clarified by treatment with activated charcoal. Thehexane was removed from this product by distillation to a pottemperature of C. at 40 mm. to give 30.0 grams of3-cyclohexen-l-ylmethyl di-o-tolyl phosphite as an undistilled residue,n 1.5516.

Analysis.Calcd: P, 8.69. Found: 8.82. Calcd equivalent weight(iodometry): 178.2. Found: 192.3, reaction mixture at a rate sufiicientto keep it just basic 191.0.

Example X VII ALLYL BLS(p-NONYLPHENYL) PHOSPHITE A solution of 60. g. ofthe bis(p-nonylphenyl) phosphorochloridite prepared in Example V in ml.of hexane was added dropwise to a stirred solution of 6.9 70 g. of allylalcohol and 0.1 g. of methyl red in 100 ml. of hexane at a ratesufiicient to maintain a temperature of from 0 to 5 C. While coolingwith an ice-salt bath. Simultaneously, dry ammonia gas was bubbled intothe 15 Example XIX Z-ETHYLHEXYL DIPHENYL PHOSPHITE Fifty grams of thediphenyl phosphorochloridite prepared in Example I was dissolved in 90ml. of hexane, and this solution was added dropwise to a stirred mixtureof 26.1 g. of 2-ethylhexanol and 0.1 g. of methyl red indicator in 90ml. of hexane at a sufiicient rate to maintain a temperature of from to5 C. while cooling with an ice-salt bath. Simultaneously, dry ammoniagas was bubbled into the reaction mixture at a sufiicient rate to keepthe solution just basic to methyl red. Thirty minutes was required forthis addition. The reaction mixture was stirred for an additionalminutes, and the tempera ture was allowed to increase to about 10 C.

To the vigorously stirred mixture was then added 150 ml. of a 10%solution of sodium hydroxide, and stirring was continued for 10 minutes.The water and oil layers were then separated and the oil layer was freedof hexane by distillation to a pot temperature of 90 C. at 20 mm. Theremaining oil on distillation gave 51.5 g. of 2-ethylhexyl diphenylphosphite, 11 1.5207, r1 1.054, B.P. 14 8156 C./0.15 mm.

Analysis.-Calcd equivalent 173.3. Found: 193.5.

Example XX 2-ETHYLHEXYL DI-o-TOLYL PHOSPHITE A solution of 28.1 g. ofdi-o-tolyl phosphorochloridite from Example III, in 45 ml. of hexane wasadded dropwise to a stirred solution of 13.5 g. of Z-ethylhexanol and0.1 g. of methyl red indicator in 45 ml. of hexane at a rate sufiicientto maintain a temperature of from 0 to 10 C. while cooling with anice-salt bath. Simultaneously, dry ammonia gas was bubbled into thereaction mixture at a rate sufiicient to keep the solution just basic tomethyl red. Twenty-two minutes was required for this addition. Thereaction mixture was stirred for an additional 15 minutes, and thetemperature was allowed to increase to about C. The ammonium chloridewas then removed by filtration, and the filtrate was freed of hexane bydistillation to a pot temperature of 100 C. at 20 mm. Distillation ofthe residue gave 33 g. of 2-ethylhexy1 di-o-tolyl phosphite, n 1.5164,a?" 1.027, B.P. 146-150 C./0.05 mm.

Analysis.Calcd equivalent weight 187.2. Found: 194.0, 193.3.

Example XXI 2-ETHYLHEXYL DI-p-TOLYL PHOSPHITE Twenty-eight grams of thedi-p-tolyl phosphorochloweight (iodometry) (iodometry) ridite preparedin Example II was dissolved in 45 n11. of hexane, and this solution wasadded dropwise to a stirred mixture of 13.5 g. of Z-ethylhexanol, and0.1 g. of methyl red indicator in 45 ml. of hexane at a sufiicient rateto maintain a temperature of from 0 to 5 C. while cooling with anice-salt bath. Simultaneously, dry ammonia gas was bubbled into thereaction mixture at a rate sufficient to keep it just basic to methylred. Twenty-five minutes was required for this addition. The reactionmixture was stirred for an additional 10 minutes, and the temperaturewas allowed to increase to about 10 C.

To the vigorously stirred mixture was added ml. of 5% sodium hydroxidesolution, and stirring was continued for 10 minutes. The water layer wasseparated, and the hexane was removed by distillation to a pottemperature of 100 C. at 20 mm. Distillation of the residue gave 26.9 g.of Z-ethylhexyl di-p-tolyl phosphite, n 1.5l91, (1 1.032.

Analysis.Calcd: P, 8.27. Found: 8.22. Calcd equivalent weight(iodometry): 187.2. Found: 198.6, 197.8.

Example XXII .Z-ETHYLHEXYL BIS (p-O CTYLPHENYL) PHOSPHITE A solution of36.2 g. of the bis(p-octylphenyl) phosphorochloridite prepared inExample IV in ml. of hexane was added dropwise to a stirred solution of9.9 g. of Z-ethylhexanol and 0.1 g. of methyl red indicator in 75 ml. ofhexane at such rate as to keep the temperature of the reaction mixtureat from 8 to 12 C. while cooling with an ice-salt bath. Simultaneously,dry ammonia gas was bubbled into the reaction mixture at a sufficientrate to keep the solution just basic to methyl red. Fifty minutes wasrequired for this addition. The reaction mixture was stirred for anadditional 15 minutes, and the temperature was allowed to increase toabout 20 C. The ammonium chloride was removed by filtration, and thefiltrate was decolorized by treatment with activated charcoal, and thenfreed of hexane by distillation to a pot temperature of C. at 20 mm.Thirtythree grams of Z-ethylhexyl bis(p-octylphenyl) phosphite wasobtained as an undistilled product, n 1.5037, d 0.9 60.

Analysis.-Calcd equivalent weight (iodometry): 285.4. Found: 339, 336.

The table below gives experimental and analytical data on additionalmonoalkyl diaryl phosphites that were prepared by the same generalexperimental procedure as shown previously.

MONOALKYL DIARYL PHOSPHITES OF THE GENERAL FORMULA Identifying variablesMolar ratio Reaction Temp. Amt. Amt.

alcohol: time range 3.5% 10% Percent chloridite min. C.) NaOH NaOH yieldR R1 R1 R; m n used (1111.) used (mL) n-Octyl Ff H Isopr0pyl. 1 2 1.0:1. 0 15 5-10 44. 5 8 9 84. 7 o H H tert-Butyl 1 2 1. 0:1 0 20 10-15 7515 90.7

Nonyl H H Fl 1 2 1.0:1. 0 6 1015 62.5 12. 5 89.0 Do H or CH H or CH H orOH; 1 2 1.021. 0 10 10-15 62.5 12.5 83.1 Do Ff H OctyL. 1 2 1.0:1.0 100-10 41.9 8.4 09.4 Decyl- 1 2 1. 0:1. 0 10 10-15 62. 5 12. 5 83.0 o H orCH H or 011 H or CH 1 2 1. 0:1. 0 10 1015 50 10 85. 3 Do 1 2 1.0:1.0 150-10 41.9 8.4 99.0 Octadeeyl H H IsopropyL. 1 2 1. 0:1. 0 15 10-15 44. 58. 9 90. 6

Do H H tert-Butyl 1 2 1. 0:1. 0 10 15-20 83. 3 16. 6 7

Identifying variables Equivalent weight Analytical (percent) 7LD C. (14R R1 R2 R3 m n Calcd. Found Galcd. Found H H Isopropyl. l 2 215.32610,2620 7m 1.5100 H H tart-11mm... 1 2 229.3 267, 268.3 un 1.5091

1 2 150.1 192.6,193.0 1 1 5158 1 2 194. 2 22s. 5, 227. up 1. 5095 1 2277. 4 334. 0. 344. 0 7113 1. 5010 1 2 187.1 1990,1990 1m 1 5138 1 2201.2 19.0,2220 7113 1 5095 1 2 299.4 352. 0, 360 0 up 1 5010 1 2 285.4373.2870 0 I56 H H tert-ButyLnn 1 2 299.4 3580,3535 71D!" 1.4930 Thegeneral experimental write-up below shows the 20 a pot temperature of 90C. at 20 mm. The resulting procedure used in the preparation oftechnical mixtures of diaikyl monoaryl phosphites with monoalkyl diarylphosphites, along with the previously mentioned small amounts of triarylor trialkyl phosphites.

The appropriate mixture of mono and diaryl phosphorochioridite, alone ordissolved in an inert solvent, was added dropwise, with stirring, to atleast a chemically equivalent amount of the appropriate alcohol. Thealcohol was diluted with an inert solvent, or excess alcohol was used asits own solvent. A suflicient amount of methyl red indicator was presentto denote change from basicity to acidity. Reaction temperature variedfrom about C. to about 20 C. Simultaneously with the addition of thephosphorochloridite mixture, dry ammonia gas was bubbled into thereaction mixture in an amount sufficient to maintain the reactionmixture just basic to methyl red.

Upon completing the addition, stirring was continued for a short period.Total reaction time varied from about minutes to about 70 minutes.

The ammonium chloride was removed by filtration or by washing with thecalculated amount of 3.5% NaOH solution and 10% NaOH solution. Thefiltrate was clarified by treatment with activated charcoal.

The oil residue was freed of inert solvent or excess alcohol by reducedpressure distillation at a pot temperature of 90 95 C. and at -60 mm.pressure, leaving the product as a residue.

Our invention is illustrated with respect to both the broad process andthe relatively limited groups of useful mixtures by the followingexamples:

A. PHOSPHITE MIXTURES PREPARED FROM THE REACTION PRODUCT OF 2 MOLES OFPHENOL AND 1 MOLE OF PCl Example XXIII TECHNICAL MIXTURE OF Z-ETHYLHEXYL313(1)- OCTYLPHENYL) PHOSPHITE AND BIS(2-ETHYL HEXYL) FCCDYLPHENYLPHOSPHITE FROM 2 :1 MIXTURE OF THE PHENOL AND PCla tion just basic tomethyl red. Twenty-five minutes was required for this addition. Thereaction mixture was stirred for an additional 10 minutes, and thetemperature was allowed to increase to about 20 C. The mixture wasfiltered to remove ammonium chloride, and the filtrate was decolorizedby treatment with activated charcoal. 'Finally, the hexane was removedby distillation to product weighed 54.3 g.

AnaL-Equivalent weight (iodornetry): Found-420, 421.

Example XXIV TE CHIJICAL MIXTURE OF ALLYL BIS (p-OC'IYLPHENYL)PI'TQSPHITE AND DTALLYL p-OCTYLPHENYL PLEIOS- PHITE FROBI 2 I1 EIIXTUREOF THE PI'IENOL AND PCls A solution of 47.7 g. of the mixture ofp-octylphenyl phosphorochloridites from Example VI, which contained 2.47milliequivalents of reactive chlorine per gram, was made up in 75 ml. ofhexane. This was added dropwise to a stirred solution of 6.9 grams ofallyl alcohol and 0.1 g. of methyl red indicator in 75 ml. of hexane ata rate sufficient to maintain a temperature or" from 10 to 15 C. whilecooling with an ice-salt bath. Simultaneously,-dry ammonia gas wasbubbled into the reaction mixture at a rate sufiicient to keep thesolution just basic to methyl red. A period of 27 minutes was requiredfor this addition. The reaction mixture was stirred for an additional 15minutes, and the temperature was allowed to increase to about 20 C. Theammonium chloride was removed from the reaction mixture by filtration,and the filtrate was clarified by treatment with activated charcoal. Thehexone was removed from the product by distillation to a pot temperatureof 95 C. at 50 mm. to give 49.9 g. of product; n l.5152, 0' 0.997.

Anal.-Equivalent weight (iodometry): Found-372, 365.

Example XXV A solution of 28 g. of the mixture of phosphorochloriditesprepared in Example VIII in 75 ml. of hexane was added dropwise to astirred solution of 13 g. of Z-ethylhexanoi and 0.1 g. of methyl redindicator in 75 ml. of hexane at a suficient rate to maintain atemperature of from 10 to 15 C. while cooling with an ice-salt bath.Simultaneously, dry ammonia gas was bubbled into the reaction mixture ata sufiicient rate to keep it just basic to methyl red. A period of 28minutes was required for this addition. The reaction mixture was.stirred for an additional 10 minutes, and the temperature was allowed toincrease to about 20 C. The ammonium chloride was removed from thereaction mixture by filtration, and this filtrate was then clarified bytreatment with activated charcoal. The hexane was removed bydistillation to a pot temperature of C. at 20 mm. The yield ofundistilled product amounted to 371g.

AnaZ.---Equivaient weight (iodornetry). Found-256, 260.

sperms Example XXVI TECHNICAL MIXTURE OF ISOOCTYL MIXED Dl-zn (AND Fortygrams of a mixture of m and p)-tolyl phosphorochloridites similar tothat prepared in Example VIII, and containing 3.66 milliequivalents ofreactive chlorine per gram, was dissolved in 65 ml. of hexane. Thissolution was added to a stirred solution of 19.05 g. of isooctyl alcoholand 0.1 g. of methyl red indicator in 65 ml. of hexane at a ratesufiicient to keep the temperature at from to C. while cooling with anice-salt bath. Simultaneously, dry ammonia gas was bubbled into thereaction mixture at a rate sufiicient to keep it just basic to methylred. A period of minutes was required for this addition.

To the vigorously stirred reaction mixture was added 36.7 ml. of 3.5%sodium hydroxide solution, and stirring was continued for 5 minutes. Thewater and oil layers were separated, and the oil layer was washed asecond time in a manner similar to the above with 7.3 ml. of 10% sodiumhydroxide solution. The oil layer was then freed of hexane bydistillation to a pot temperature of 95 C. at mm. The resulting residuewas vacuum distilled to give 41.1 g. of product, B.P. 157165 C./0.07

AnaL-Equivalent Weight (iodometry): Found-494.

Example XXVII TECHNICAL MIXTURE OF OLEYL DI-MIXED m (AND p)-TOLYLPHOSPHITE AND DIOLEYL MIXED 111 (AND p)-TOLYL PHOSPHITE FROM 2 :1MIXTURE OF THE PHENOL AND PCla A solution of 28.0 g. of the mixture of m(and p)-toly1 phosphorochloridites prepared in Example VIII in 75 ml. ofhexane was added dropwise to a stirred solution of 26.9 g. of oleylalcohol and 0.1 g. of methyl red indicator in 75 ml. of hexane at a ratesufiicient to maintain a temperature of 10 C.i2 C. while cooling with anice-salt bath. Simultaneously, dry ammonia gas was bubbled into thereaction mixture at a rate sufficient to keep the solution just basic tomethyl red. A period of 27 minutes was required for this addition. Thereaction mixture was stirred for an additional 15 minutes, and the temperature was allowed to increase to about 20 C. The ammonium chloridewas removed from the reaction mixture by filtration, and the filtratewas clarified by treatment with charcoal. The hexane was removed fromthis product by distillation to a pot temperature of 90 C. at 60 mm. togive 45.4 g. of product, n 1.5050, (1 0.970.

AnaI.-Equivalent weight (iodometry): Found-348, 355.

Example XX VIII TECIINICAL MIXTURE OF Z-ETHY LHEXYL DIPIIENYL PHOSPHITEAND BIS (Z-ETHYLI'IEXYL) PHENYL PHOSPHIT'E FROM 2:1 MIXTURE OF THEPHENOL AND PCla A solution of 252.6 g. of the mixture of phenylphosphorochloridites prepared in Example X in 500 ml. of hexane wasadded dropwise to a stirred solution of 110.0 g. of Z-ethylhexanol and0.1 g. of methyl red in 500 ml. of hexane at a rate sufficient tomaintain a temperature of from 5 to 10 C. while cooling with an ice-saltbath. Simultaneously, dry ammonia gas was bubbled into the reactionmixture at a sufiicient rate to keep the solution just basic to methylred. A period of 45 minutes was required for this addition. The reactionmixture was stirred for an additional 10 minutes, and the temperaturewas allowed to increase to about 20 C. The ammonium chloride was removedfrom the reaction mixture by filtration, and the filtrate was clarifiedby treatment with activated charcoal. The hexane was removed bydistillation to 20 a pot temperature of 95 C. at 50 mm. to give 301 g.of technical product: 11 1.5247, df 1.058.

Anal.Equivalent weight (iodometry): Found-222.

Example XXIX TECHNICAL MIXTURE OF OLEYL DIPHENYL PHOS- IHITE AND DIOLEYLPHENYL PHOSPHI'IE FROM 2 :1 MIXTURE OF THE PHENOL AND PO13 A solution of25.3 g. of the mixture of phenyl phosphorochloridites prepared inExample X in ml. of hexane was added dropwise to a stirred solution of33.1 of oleyl alcohol and 0.1 g. of methyl red indicator in 75 ml. ofhexane at a rate sufficient to maintain a temperature of 10 0:2" C.while cooling with an ice-salt bath. Simultaneously, dry ammonia gas wasbubbled into the reaction mixture at a rate sufiicient to keep thesolution just basic to methyl red. A period of 26 minutes was requiredfor this addition. The reaction mixture was stirred for an additional 15minutes, and the temperature was allowed to increase to about 20 C. Theammonium chloride was removed from the reaction mixture by filtration,and the filtrate was clarified by treatment with activated charcoal. Thehexane was removed from this product by distillation to a pottemperature of 95 C. at 40 mm. to give 47.0 grams of product, a 1.4988,r1 0.960.

Anal-Equivalent weight (iodometry): Found--388, 382.

B. PHOSPI-IITE MIXTURES PREPARED FROM THE REACTION PRODUCT OF 1 MOLE OFPHENOL AND 1 MOLE OF PO1 Example XXX TECHNICAL MIXTURE 0FBIS(2-ETHYLHEXYL) p- OCTYLPHENYL PHOSPHITE AND 2-ETHYLHEXYLBIS(p-OCTYLPHENYL) PHOSPHITE FROM 1:1 MIX- TUBE OF THE PHENOL AND PCle Asolution of 47.7 g. of a mixture of undistilled poctylphenylphosphorochloridites prepared as described in Example VII, whichcontained 4.59 milliequivalents of reactive chlorine per gram, was madeup in 75 ml. of hexane. This was added dropwise to a stirred solution of28.5 g. of 2-ethylhexanol and 0.1 g. of methyl red indicator in 75 ml.of hexane at a sufficient rate to maintain the temperature at 15 C.while cooling with an icesalt bath. Simultaneously, dry ammonia gas wasbubbled into the reaction mixture at a sufficient rate to hold thereaction mixture just basic to methyl red. A period of 28 minutes wasrequired for this addition. The reaction mixture was stirred for anadditional 10 minutes, and the temperature was allowed to increase toabout 20 C. The ammonium chloride was removed by filtration, and thefiltrate was decolorized by treatment with activated charcoal. Thehexane was removed by distillation to a pot temperature of C. at 20 mm.The final undistilled product weighed 54 g.

Anal.--Equivalent weight (iodometry): Found356.5, 350.5.

Example XXX] TECHNICAL MIXTURE 0F DIOLEYL p-OCTYLPHENYL PHOSPHITE ANDOLEYL BIS(p-OCTYLPHENYL) PHOSPHITE FROM 1:1 MIXTURE OF THE PHENOL ANDPCla A solution of 23.8 g. of the mixture of p-octylphenylphosphorochloridites from Example VII, which contained 4.59milliequivalents of reactive chlorine per gram, was made up in 75 ml. ofhexane. This was added dropwise to a stirred solution of 29.4 g. ofoleyl alcohol and 0.1 g. of methyl red indicator in 75 ml. of hexane ata rate sumcient to maintain a temperature of l0i2 C. while cooling withan ice-salt bath. Simultaneously, dry ammonia gas was bubbled into thereaction mixture at a rate sufficient to keep the solution just basic tomethyl red. A period of 24 minutes was required for this addition. The

reaction mixture was stirred for an additional 15 minutes, and thetemperature allowed to increase to about 20 C. The ammonium chloride wasremoved from the reaction mixture by filtration, and the filtrate wasclarified by treatment with activated charcoal. The hexane was removedfrom the product by distillation to a pot temperature of 95 C. at 6 mm.to give 50.9 g. of product: 11 14830, d 0.917.

Anal.-Equivalent weight (iodometry): Found-356, 361.

Example XXXII TECHNICAL MIXTURE OF BIS(2-ETI-IYLHEXYL) MIXED m (ANDp)-TOLYL PHOSPHITE AND :ZETHYLHEXYL DIMIXED m (AND p)-TOLYL PHOSPHITEFROM 1 :1 MIXTURE OF THE PHENOL AND Pcu A solution of 42 g. of themixture of m (and p)-tolyl phosphorochloridites prepared in Example IXin 75 ml. of hexane was added dropwise to a stirred solution of 39.8 g.of Z-ethylhexanol and 0.1 g. of methyl red indicator in 75 ml. of hexaneat a sufiicient rate to maintain a temperature of from to 15 C. whilecooling with an ice-salt bath. Simultaneously, dry ammonia gas wasbubbled into the reaction mixture at a sufficient rate to keep it justbasic to methyl red. A period of 42 minutes was required for theaddition. The reaction mixture was stirred for an additional 10 minutes,and the temperature was allowed to increase to about C. The ammoniumchloride was removed by filtration. The filtrate was clarified bytreatment with activated charcoal, and then freed of hexane bydistillation to a pot temperature of 90 C. at 20 mm. The resultingundistilled product weighed 61.6 g.

Anal.-Equivalent 276.5, 277.0.

weight (iodometry) Pound- Exampl XXXIII TECHNICAL MIXTURE OF DIOL'EYLariXnD m (AND p) TOLYL PHOSPl-IITE AND OLEYL "DI-MIXED m (AND y'ioL-YLPHOsPHITE FROM 1:1 MIXTURE OF Tire; PHENOL AND PCla A solution of 28 g.of the mixture of m (and p)-tolyl phosphorochloridites prepared inExample lX in 75 ml. of hexane was added dropwise to a stirred solutionof 54.6 g. of oleyl alcohol and 0.1 g. of methyl red indicator in 75 ml.of hexane at a rate suificient to maintain a temperature of 10 C.:t2 C.while cooling with an ice-salt bath. Simultaneously, dry ammonia gas wasbubbled into the reaction mixture at a rate sufficient to keep thesolution just basic to methyl red. A period of 26 minutes was requiredfor this addition. The reaction mixture was stirred for an additional 15minutes, and the temperature was allowed to increase to about 20 C. Theammonium chloride was removed from the reaction mixture by filtration,and the filtrate was clarified by treatment with activated charcoal. Thehexane was removed from this product by distillation to a pottemperature of 90 C. at 60 mm. to give 65.5 g. of product: 11 1-4823, d0.923.

Anal-Equivalent weight (iodometry): Found-469, 439.

Example XXXIV TECHNICAL MIXTURE OF BIS(2-ETHYLHIDXYL) PHEX- Y1;PHOSPHI'TE AND ZETHYLHEXYL DIPHENYL PHOSPHITE FROM 1:1 MIXTURE OF THEPHENOL AND PCla A solution of 195 g. of the mixture of phenylphosphorochloridites prepared in Example XI in 500 ml. of hexane wasadded dropwise to a stirred solution of 174.2 g. of Z-ethylhexanol and0.1 g. of methyl red indicator in 500 m1. of hexane at a rate sufficientto keep .e temperature at from 10 to 15 C. while cooling with an icesaltbath. Simultaneously, dry ammonia gas was bubbled into the reactionmixture at a rate sufiicient to maintain it just basic to methyl red. Aperiod of 60 minutes (iodometry) Found- Example XXXV TECHNICAL MIXTUREOF DIOLEYL PHENYL PHOS- PHI'lE AND OLEYL DIPHENYL PHOSPHITE FRGM 1 :1.MZKTURE OF THE PHENOL AND PCls A solution of 25.3 g. of the mixture ofphenyl phosphorochloridites prepared in Example XI in ml. of hexane wasadded dropwise to a stirred solution of 44.6 g. of oleyl alcohol and 0.1g. of methyl red indicator in 75 ml. of hexane at a rate sufficient tomaintain a temperature of 10 C.- L5 C. while cooling with an ice-saltbath. Simultaneously, dry ammonia gas was bubbled into the reactionmixture at a suflicient rate to keep the solution just basic to methylred. A period of 24 minutes was required for this addition. The reactionmixture was stirred for an additional 15 minutes, and the temperaturewas allowed to increase to about 20 C. The ammonium chloride was removedfrom the reaction mixture by filtration, and the filtrate was clarifiedby treatment with activated charcoal. The hexane was removed from thisproduct by distillation to a pot temperature of C. at 45 mm. to give53.7 g. of product, 11 1.4882, (1 0.943.

Anal-Equivalent weight (iodometry): Found-386, 391.

As appears from the foregoing disclosure, the process of this inventionis applicable generally for the production of aliphatic aryl triestersof phosphorous acid by the reaction of an aryl phosphorohalidite withvarious alcohols including mono-, diand polyhydroxy alcohols, primaryand secondary alcohols in which the hydrocarbon group is straight chainor branched, saturated and unsaturated alcohols and alcohols in whichhydrogen of the hydrocarbon group is unsubstituted or substituted byinactive substituents such as halogen. No limit has been found and noneappears probable as to the size of the aliphatic group R at least up tothose having about 18 carbon atoms.

As also appears from the foregoing closure, the process of thisinvention is applicable for the production of allphatic aryl tricstersof phosphorous acid which contain a wide variety of aryl groups. Bystarting with the proper aryl phosphorohalidite, triesters can be madewhich contain either one aryl group or two aryl groups which may or maynot be identical. No limit has been found and none appears probable asto the. chain length of alkyl substituent R, on the aryl nucleus atleast up to aryl groups containing substituents having 20 carbon atoms.

While the use of inert solvent or excess of the dcohol or both is notessential, such use is an important feature of the process from thestandpoint of economical production of the triesters.

The temperature at which the reaction is carried out, like the use ofsolvent, also is not the essence of the invention, but is importantparticularly when correlated with the use of solvent, the degree ofagitation, the type of aryl phosphorohalidite employed and the size ofthe aliphatic group in determining the optimum conditions for operationof the process.

While the description has dealt more particularly with the addition ofan aryl phosphorochloridite to a body of the alcohol in the presence orabsence of inert solvent and with simultaneous addition of anhydrousammonia at such a rate as to maintain the reaction mixture substantiallyneutral, the reaction may be carried out by a simultaneous addition ofan aryl phospborohalidite and an alcohol to a reaction space which mayat the start be empty or may contain some of the alcohol and/ or inertsolvent provided that anhydrous ammonia also is added at such a rate asto maintain the reaction mixture substantially neutral and providedfurther than an excess of the. aryl pbosphorohalidite in the reactionmixture is avoided.

This application is a division of our application Serial No. 579,777filed April 23, 1956, now abandoned, which application is in turn acontinuation-in-part of our application Serial No. 423,536 filed April15, 1954, now US. Patent No. 2,866,807, granted December 30, 1958.

We claim:

1. As a new composition of matter, a mixture of GRS rubber and acompound of the formula in which R is a member selected from the groupconsisting of octyl, allyl, oleyl and 3-cyclohexen-l-ylmethyl, R is analkyl having from 1 to 9 carbon atoms and m and n are integers the sumof which is 3, said compound being present in an amount sufficient tostabilize said rubber.

2. As a new composition of matter, a mixture of GRS rubber and octylbis(octylphenyl) phosphite, said phosphite being present in an amountsufficient to stabilize said rubber.

3. As a new composition of matter, a mixture of GRS rubber and2-ethylhexyl bis(p-octylphenyl) phosphite,

24 said phosphite being present in an amount sufiicient to stabilizesaid rubber.

4. As a new composition of matter, a mixture of GRS rubber andbis(octyl)mono-(octylphenyl) phosphite, said phosphite being present inan amount sufiicient to stabilize said rubber.

5. As a new composition of matter, a mixture of GRS rubber andbis(2-ethylhexyl)mono-(octylphenyl) phosphite, said pbospbite beingpresent in an amount sufficient to stabilize said rubber.

6. As a new composition of matter, a mixture of GRS rubber andbis(2-ethylhexyl)p-( 1,1,3,3-tetramethylbutyl)- phenyl phosphite, saidphosphite being present in an amount sufficient to stabilize saidrubber.

7. As a new composition of matter, a mixture of GRS rubber and allylbis(nonylpbenyl) phosphite, said phosphite being present in an amountsufiicient to stabilize said rubber.

8. As a new composition of matter, a mixture of GRS rubber andbis(2-ethylhexyl)tolyl phosphite, said phosphite being present in anamount suflicient to stabilize said rubber.

9. As a new composition of matter, a mixture of GRS rubber and allylditolyl phosphite, said phosphite being present in an amount sufiicientto stabilize said rubber.

References Cited in the file of this patent UNITED STATES PATENTS

1. AS A NEW COMPOSITION OF MATTER, A MIXTURE OF GRS RUBBER AND ACOMPOUND OF THE FORMULA